🔋 Solar Autonomous Grass Cutter
An eco-friendly autonomous lawn mower featuring solar charging tracking and a grid pathing coverage algorithm.
Overview
Green energy makes agricultural machinery completely self-sustaining. This project constructs an autonomous solar lawn mower featuring automated path coverage (zig-zag routing), battery protection, and obstacle-avoidance.
What you'll learn: Sizing solar arrays, grid routing path algorithms, high-torque PWM DC motor drivers, battery discharge safety cut-offs, and ultrasonic bumpers.
Estimated time: 10+ hours. Difficulty: ⭐⭐⭐⭐⭐ Expert.
Components Needed
| Component | Specification | Qty | Notes |
|---|---|---|---|
| ESP32 Development Board | Fast multi-thread core | 1 | Manages navigation & charger telemetries |
| 12V Solar Panel & Controller | 10W / 12V Battery out | 1 | Charges battery off-grid |
| 12V DC High-Torque Motors | 200 RPM, high reduction | 2 | Wheels drive |
| 12V DC Cutter Blade Motor | High speed, 3000 RPM | 1 | Spins grass cutter blades |
| BTS7960 Motor Driver | 43A Dual H-Bridge | 1 | Drives high-current cutter motor safely |
| HC-SR04 Sensors | Ultrasonic | 3 | Bumper arrays (Left, Center, Right) |
Step-by-Step Tutorial
1
Drive System Assembly
Mount high-torque wheel motors on a rigid chassis. Install the high-speed central cutting blade motor underneath, secured by safety shields.
2
Wire Solar & Battery Charging
Connect the 12V solar panel to the solar charge controller. Wire the output to a 12V rechargeable Lead-Acid/LiFePO4 battery.
3
Configure Motor Drivers
Connect the wheel motors to an L298N driver. Wire the high-current cutter motor to the BTS7960 driver, controlled by ESP32 PWM pins.
4
Implement Grid Pathing Algorithm
Write a zig-zag field coverage navigation routine. The robot drives forward until the ultrasonic bumpers register a perimeter, performs a 180-degree turn, offsets, and travels back.
5
Safety Failsafe Integrations
Write a voltage sensor routine. If the battery drops below 10.5V, immediately shut down the high-speed cutter motor to prevent deep battery discharge.
Lawn cutter blades possess immense kinetic energy. Keep safety bumper microswitches wired in series with the cutter driver enable pin, allowing physical bumps to cut blade power immediately.
Code / Configuration
solar_mower.ino
INO
// Solar Autonomous Mower - Volt X
const int trigPin = 12;
const int echoPin = 13;
const int cutterPWM = 25; // Cutter motor speed
const int motorL1 = 26;
const int motorL2 = 27;
void setup() {
Serial.begin(115200);
pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT);
pinMode(cutterPWM, OUTPUT);
pinMode(motorL1, OUTPUT);
pinMode(motorL2, OUTPUT);
// Start cutter blades
analogWrite(cutterPWM, 200);
}
void loop() {
long duration, distance;
digitalWrite(trigPin, LOW); delayMicroseconds(2);
digitalWrite(trigPin, HIGH); delayMicroseconds(10);
digitalWrite(trigPin, LOW);Reviews & Ratings
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